The field of material microstructural design to achieve a set of targeted mechanical and functional properties has become a mainstay of new material development strategies. Structural materials, which by their very nature are intended to carry mechanical loads in service, can be designed to provide additional performance-enhancing functions through tailoring of meso-, micro-, or nano-structures. Structural materials with these performance-enhancing capabilities have been termed “synthetic multifunctional materials.” Structural composites, by their multiphase nature, offer many opportunities for the design of performance-enhancing multifunctional materials. Recently, a new class of structural materials has been developed at the University of California, San Diego, termed metallic-intermetallic laminate (MIL) composites.2 The goal of this materials development effort was to extrapolate upon the positive engineering properties exhibited by hierarchical multiphase complex natural composites, such as mollusk shells,3,4 to design and synthesize multifunctional composites to optimize specific structural properties while facilitating low-cost, designable, and functional microstructures.